1. Field of the Invention
This invention relates to a chip carrier maker, more particularly to a blow molding apparatus for a chip carrier maker, whereby a longitudinal row of spaced-apart recesses is formed in a thermoplastic strip by the pressure of compressed hot-air.
2. Description of the Related Art
Referring to FIGS. 1A, 1B and 2, a thermoplastic narrow strip 1 or wide strip 2 is formed by a conventional chip carrier maker 3. The narrow strip 1 has a longitudinal row of spaced-apart rectangular recesses 11 formed in an upper surface thereof, and a plurality of holes 12 formed therethrough. The wide strip 2 has two longitudinal rows of spaced-apart rectangular recesses 21 and a plurality of holes 22. The maker 3 includes a strip feeding device 31 for supplying a flat thermoplastic strip 30, a blow molding apparatus which includes a heating device 32 for heating and softening the punched strip 30, and a compression mold device 33 for forming the rectangular recesses 11, 21 in the softened strip 30, a punching device 34 for forming the holes 12, 22 in the strip 30, and a strip activating device 35 for moving the strip 30 from the feeding device 31 to a strip winding device 36. When moved from the heating device 33 to the compression molding device 34, the softened strip 30 will slightly deform prior to the blow molding process due to the pull of the strip activating device 35. As a result, the rectangular recesses 11, 21 cannot be formed accurately at predetermined positions in the strip 30.